Aquatic ecology (Environmental Studies)

In recent years, with the rapid development of the global economy, heavy metals have been widely used in industrial production and daily life because of their unique properties. This, however, has simultaneously led to heavy metal pollution due to several reasons. After entering the aquatic environment, heavy metals are not easily decomposed by microorganisms and become toxic when they reach a certain concentration. Heavy metals can easily enter the liver and other vital organs of aquatic organisms, where they accumulate and severely affect the growth and reproduction of these organisms. They can also threaten human health through the food chain. Therefore, heavy metal pollution has potential ecological and health risks. This paper summarizes the sources and hazards of heavy metals in water, the pattern of enrichment of heavy metals in aquatic organisms, the toxic effects of heavy metals on aquatic organisms, the tolerance mechanism of aquatic animals to heavy metals, and the factors affecting the toxicity of heavy metals. The authors put forward three feasible suggestions for the study of ecotoxicological effects of heavy metals on aquatic organisms in the future. The results of this study have considerable significance for aquaculture and environmental management and even for humans.

A variety of chemicals including foaming agents are used to aid in the protection of forest resources from the wild land fires. The fire-fighting foams (FFFs) are formulations composed principally of surfactants. As a part of Japanese national project, environmentally inert FFFs have been developed. There is an emerging need for testing the impacts of these FFFs on the living organisms composing the typical landscapes or ecosystems in Japan. In the present report, we aimed to describe our latest attempt for assessing both the short-tem and long-term impacts of FFFs in aquatic (fresh water) and semi-aquatic (wetland) ecosystems , by employing the laboratory-sized model assays (preliminary studies) and the biotope-based observation, respectively. In the biotope assays which was based on the observation in compact biotopes mimicking the fresh water environments and wetland, both the acute and long-term eco-toxic impacts of two FFFs (soap-based and synthetic detergent-based) were assessed. Spraying of synthetic detergent-based foam formula was shown to be more toxic compared to soap-based formula and mock water treatment.

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For teaching and research purposes, in this glossary was compiled some of the terms used in studies of wetlands and aquatic ecology, by professionals and technicians of the area. Terms of daily use in Venezuela, by people who perform some type of aquatic activity or are in contact with the fauna and vegetation of aquatic environments, were also incorporated. Many terms were translated into Spanish, from the technical literature; however, others, whose translation we thought would be unfortunate, have remained in their original form.

Con fines docentes y de investigación, en este glosario se han compilado algunos de los términos usados en estudios de humedales y ecología acuática, por profesionales y técnicos del área. También se incorporaron términos de uso cotidiano en Venezuela, por personas que ejecutan algún tipo de actividad acuática, o están en contacto con la fauna y vegetación de los ambientes acuáticos. Muchos términos fueron  traducidos al castellano, a partir de la literatura técnica; sin embargo otros, cuya traducción nos pareció que resultaría desacertada, se han mantenido en su forma original.

Limbah adalah salah satu hal yang tidak disukai oleh semua orang, akan tetapi setiap hari orang-orang banyak yang mengeluarkan limbah secara tidak sadar. Miris memang jika melihat semua ini. Terbukti dengan sungai-sungai yang ada khususnya di daerah Bandung sangat tercemar baik limbah tercemar oleh limbah organik maupun limbah anorganik. Limbah pabrik dan juga limbah domestik yang berupa bahan organik akan mengakibatkan kerusakan pada struktur dan kualitas air yang mengakibatkan bidang perikanan dan pertanian akan terganggu. Sehingga dengan adanya air yang kurang sehat akibat tercemar oleh limbah maka banyak hal yang terganggu baik manusia maupun hewan terutama ikan. Hal ini terjadi karena ikan adalah salah satu organisme yang media hidupnya di dalam air. Maka dari itu perlu adanya pengelolaan air untuk mengurangi dampak yang ada. Baik dengan pengelolaan air yang merupakan sumber kehidupan maupun pengolahan dan pendayagunaan air yang sudah tercemar oleh limbah. Instalasi Pengolahan Air Limbah (IPAL) adalah salah satu instalasi yang terdapat di daerah Bojongsoang Jawa Barat, instalasi ini bergerak dalam pengolahan air limbah yang akan menghasilkan air untuk digunakan kembali baik untuk perikanan maupun pertanian. Dengan adanya IPAL ini diharapkan mengurangi dampak ataupun kekurangan hasil dari perikanan maupun pertanian yang merupakan aset yang terdapat di negara kita Indonesia

The Water Conservation Mission of Andhra Pradesh, in the process of developing the Water Vision of AP, has realized the importance of giving due weightage to the environmental and ecological concerns and needs, which then forms the foundation of the natural sustainability process.

The strategy papers of various related Government Departments, discussions with key officials in the departments, discussion with academicians, subject experts, other Water mentors, learnings from district vision collection workshops, secondary references, selected field visit and the consultant’s earlier experiences forms the basis of this paper.

Andhra Pradesh has the tropical varieties of eco-systems, from which the areas discussed in this paper are the forests (catchment area), rivers including river basins, reservoirs, ponds and tanks, natural lakes, other fresh water wetlands, estuarine and coastal systems along with the influences of development and human interventions on the same.

Though the forest area is around 23% of the land area, the actual cover of forest in Andhra Pradesh is only 44,229 Sq.km, accounting to 16.08%. Apart from the protection under wild life sanctuaries, the significant change in the recent past had been the Joint Forest Management Programmes involving people that had contributed to increase in forest cover. The forests contribute to recharging the river basins, at the same time is dependent on the natural water resources for its density and biodiversity. The suggestion would be to take up Forest Management on a river basin basis, so that each river basin may have sufficient forest cover. Barren hills and waste lands should get afforested.

40 rivers and drains are identified in Andhra Pradesh of which except for Godavari the water resources of most other rivers are almost used up. The major threat to river ecology is pollution. Pollution is from sewage, industries, agricultural and aquaculture runoffs. It has reached threatening levels in river/drains like Musi, Nakavagu etc., and showing risky levels in many points in many rivers as Godavari and Krishna. Sewage treatment and industrial effluent treatment should not be compromised at all

Though there are varied suggestions, scientific estimation and assurance of minimum instream flow for ecological and environmental needs is yet to be evolved in Andhra Pradesh, which needs utmost priority.

The Riverine faunal biodiversity expressed by Fisheries biodiversity had been affected by dams, siltation, pollution and over fishing. The fishing holidays and mesh regulations are hardly able to take care of the same. Protection of the summer shelters of fish ‘madugus’ is suggested.

The ecological implication of the reservoir on a riverine system is described. Though new habitats for plankton, fishes and birds may develop, there are instances where larger breeding grounds of certain indigenous species had been affected like in Nagarjunasagar and fishes down the food chain starts dominating. The effect on the migratory fish Hilsa is also quoted. The issue of inundation of forestlands and rehabilitation of population has to be addressed properly. Though Environment Impact Assessments (EIA) is done by the Irrigation department, we need to review the past outcomes of EIA for learning for future. Appropriate preventive, mitigative or avoidance steps are suggested to address ecological problems in future projects.

Some of the Hyderabad based reservoirs set examples for gross pollution that need to be addressed as well as possibility of maintaining drinking water quality if maintained and managed well. Lake protection committees apart from regular pollution control measures are suggested.
There is gross neglect of the vast resources of ponds and tanks available in Andhra Pradesh. Sufficient participatory approaches to revive the tanks and tank ecosystems including 15% dead storage of tanks are suggested.

Many fresh water wetlands are identified in Andhra Pradesh and many of them are protected by the wildlife division of the Department of Forests. Realising the importance of wetlands in water recharge, biodiversity maintenance, water recycling, climate stabilization etc., more of people’s motivation to protect wetlands and promote constructed wetlands for managing organic wastes are suggested.

The Kolleru lake ecology had been seriously affected by pollution, siltation and above all encroachment by Fish tanks practicing intensive fish culture. Drinking water is seriously affected in the local villages. 18 species of fishes and many species of birds have disappeared. Serious catchment area management, phased withdrawal of Fish tanks within +5 contours and environmental cess on aqua culturists are proposed.

The brackish water lake of Pulicat spreading between Andhra Pradesh and Tamil Nadu faces the threat of siltation, low fresh water inflow, lesser lake water circulation due to roads and above all lesser tidal exchange due to the barmouth closure. The biodiversity and fisheries of northern area (AP) has been affected. Opening of the barmouth, more culverts along the roads across the lake and catchment treatment are some of the measures suggested. There is also a need of liasoning with the Tamil Nadu Government to check pollution from the southern end.

Among aquaculture activities that have impacts on ecology, the intensive fish culture in fresh water tanks and brackish water Shrimp culture beyond carrying capacities of the natural systems has to be addressed. The organic pollutant load including farm inputs like chemicals and pesticides (fresh water fish, culture) has to be regulated and culture system be extensive according to a master plan and in tune with the carrying capacity. The exotic catfish culture with all its ecological threat needs to be banned. The fresh water scampi culture intensified and dependent on ground water need to be regulated and spread out. More and more of the conventional village tanks and ponds could be brought under extensive fish/prawn culture with least negative impacts on ecology.

In the coastal area, a people friendly approach on the implementation of Marine Fish Regulation act, complete check on Shrimp Seed Collection, pollution control measures are some of the areas needing attention.

The Coastal Regulation Zone being controlled by the Shore Area Development Authority (SADA) needs a broader base and Integrated Coastal Zone Management approach to be effective.Protection of Mangroves in Andhra Pradesh is confined to the selected areas of Godavari and Krishna river mouths brought under Wildlife Sanctuaries by the Department of Forests where the protection is successful. The 20 eco-development clubs formed in E.Godavari district also showing good results. The concern is the mass destruction of mangroves outside the sanctuary area for various purposes mainly for shrimp culture. Measures to check this and revive the mangroves in all viable coastal areas including in the abandoned shrimp ponds are suggested.
Finally, the importance of the Integrated Water Resource Management (IWRM) of the Global Water Partnership is analysed and measures for an integrated water resource management in Andhra Pradesh from the ecology point of view suggested.

This article investigates the terraqueous entanglements of
human and marine life in material and discursive contexts through
an aquatic practice of material ecocritical theory. Material ecocriticism
encourages us to read the ecology of the planet’s protean seas by way
of their storied dimension, and to think the blue humanities and the
discoveries of marine sciences through one another, in creative ways.
In this context, two interlinked questions surface. 1. How do we theorize
the seascapes whose materiality is hydrous without obfuscating
its reality in figurative conceptualizing? 2. If our knowledge of the
sea depends on how it is represented, and interpreted, will the sea’s
biogeophysical existence cease to exist? I argue that the meanings of
the sea always remain in the interstice between the discursive and the
real, and that the experience of the sea gains meaning only in their
corollary dynamics.

Till recently, carp seed rearing and farming at any scale was highly profitable because of the low cost for the inputs.  But it no longer continues, as the cost of basic inputs like cow dung, poultry manure, ground nut cake, rice bran and land costs are increased by many folds, while the gate value of the fish seed and fish remained almost constant. To know the scale of economy and present economics of the fish rearing at different stage, the assessment was carried out in 258 villages of Southern Karnataka. It is found out that fish seed rearing for 50 days, the Benefit Cost ratio (BC ratio) in catla 1.59, rohu 2.91, common carp 2.05 and grass carp 3.4. The return on investment (RoI) is high in grass carp (2.61) followed by rohu (2.32), common carp (1.81) and catla (1.52). In fish culture for 10 months period, the BC ratio in feed based farming was 1.05 as against 0.47 in conventional feed based system and 0.53 in extensive method.  The RoI was 0.86, 0.61 and 0.29 in feed based, conventional feed and extensive method respectively. In second year, the RoI was increased to 2.05, 1.47 and 1.53 respectively. Though the rates of inputs vary from place to place, the present study gives the economic trend so that farmers, entrepreneurs can plan their scale of operation based on the resource and capital. 
Key Words: Fish seed rearing, BC Ratio, Return on Investment

The role of Indigenous knowledge of fishers in Ekperiama along Ogbia Creek was assessed for its quality between August 2013 and April 2015. Quality time was spent with the fishers to study their daily activities. During this period one of the authors (SA) embarked on monthly trips to the community where she stayed for eight days a month. She participated in the daily life of the people and worked regularly with the local fishers, to gain as wide as possible understanding of the local fishing system. Interviews were conducted on monthly basis to obtain knowledge about habitats, spawning, recruitment, fish diet, and the trophic network of the Sciaenid community. Information collected was systematically compared with that of scientific information collected in parallel surveys and with published data for reliability. Indigenous knowledge compared favourably with scientific knowledge in the different areas investigated. In the event of limited resources, Indigenous knowledge could be used as a supplementary source of scientific studies and basis for new scientific investigation to obtain knowledge relating to the entire creek.

1. The Ephemeroptera fauna of the World consists of 42 families, 400 genera and 3000 species, while the Ephemeroptera fauna of the Turkey consists of 14 families, 39 genera, 138 species and 5 subspecies.
2. The Ephemeroptera species of Turkey constitutes 4,6% of the Ephemeroptera species in the World.
3. With respect to the genera number, Ephemeroptera genera of Turkey constitutes 9,75%
of the Ephemeroptera genera in the World.
4. Ephemeroptera species play a critical role in order to define the reference sites and their fauna concerning the application of European Union Water Framework Directive (EUWFD) in Turkey.

This research aims to study the acute and sub-chronic effects of the plant extracts on fin-gerlings and juveniles of Clarias gariepinus as they are used as potential drugs against the parasites. Quantitative and qualitative analyses of the extracts of seven plants; Piper guineense, Aframomum melegueta, Moringa oleifera, Gongronema latifolium, Azadirachta indica, Garcinia kola and Xylopia aethiopica and their potencies against C. gariepinus, helminth parasites and microorganisms were investigated. The study revealed the presence of alkaloids, flavonoids, saponins, tannins, phlobatan-nins, cardiac glycosides, anthraquinones and terpenoids. A 96 h acute toxicity of the extracts on fish juveniles was determined. Parasites were recovered from 60 samples of C. gariepinus obtained from Lekki lagoon. The low observed effect concentration of the extracts was also tested against the parasites , Staphylococcus aureus, Shigella flexneri, and Pseudomonas aeruginosa using standard methods. Average Survival Time (AST) for the parasites was estimated. Relative Toxicity Factors (RTFs) of the extracts at Low Observed Effect Concentration (LOEC) – 96 h LC 5 mg/l occurred in this trend; X. aethiopica (RTF, 1.0) < G. latifolium (RTF, 2.0) < A. indica (RTF, 2.0) < G. kola (RTF, 2.0) < M. oleifera (RTF, 2.0) < P. guineense (RTF, 5.0) < A. melegueta (RTF, 8.0). Parasites recovered from C. gariepinus include cestode (Wenyonia minuta), and nematode (Procamallanus longus). It was observed that only A. melegueta and A. indica slightly inhibited the growth of S. flex-neri and P. aeruginosa. The potency of the extracts and Average Survival Time (AST) of intestinal parasites occurred in this trend; X. aethiopica < G. latifolium < A. indica < G. kola < M. olei-fera < P. guineense < A. melegueta. A 95 h LC 2.5 of A. melegueta (32 mg/l) being the most toxic extract was used to carry out histopathology on the fish gills. The gills exposed showed some pathological effects. This study confirms that the extracts of the seven plants exert anthelminthic property, but choice of extract and its toxicological risk on the fish host is highly essential.

ABSTRACT
Physico-chemical and primary productivity studies were undertaken at the northern reverine segment of the Volta Lake, Yeji, at two southernmost lacustrine areas (Kpando-Tokor and Dzemeni) and one below the dam (Kpong Headpond). The studies were conducted from June 2006 to April 2008 at different depths (0, 2, 4, 6 and 8 m). The mean surface dissolved oxygen levels at the 4 stations were comparable and varied between 7.3 and 8.1 mgL-1. Dissolved oxygen decreased with increasing depth but with considerable amount of oxygen detected even at 12 m depth, indicating a well oxygenated Lake. Mean pH values ranged from 6.8 to 7.7. Transparency values ranged from 20 to 320 cm with Yeji recording relatively low values. Compared with earlier studies, transparency had reduced over the years at Yeji due to increase in suspended particles as a result of human activities. Concentrations of chemical constituents at 100 m from the shores of the Lake were similar to that of 500 m, suggesting a well mixed Lake. Generally, the nutrient levels in the Volta Lake were low indicating that the Lake is not eutrophic. The average values of temperature, pH and dissolved oxygen are considered suitable for normal aquatic life. A total of 73 algal taxa were encountered during the study. These include 37 Green algae (Chlorophyta), 50.68%; 16 Blue-Green algae (Cyanophyta) 21.92% and 20 Diatoms (Bacillariophyta) 27.40%. Yeji was richer in Green algae (27 taxa) compared to Dzemeni and Kpando-Tokor (24 and 23 each) which were similar in green algae diversity. The Blue-Green algae and the Diatoms were about evenly occurring at the three stations on the Lake. Kpong Headpond was richer in Green and Blue-Green algae compared to stations on the main lake.
Key words: Physico-chemical, water quality, primary productivity, algae, diatoms, Lake Volta.
INTRODUCTION

Laubuka laubuca (Hamilton 1822) is a poorly studied freshwater fish found in South and Southeast Asia. This study was conducted to investigate the feeding habit and length-weight relationship of L. laubuca at Maguru Oya Stream, Sri Lanka. Gut contents of 180 fish were analysed, and food particles identified were categorised into 15 broad taxonomic groups. Relative abundance of each food category was calculated for 1-3, 3-5 and >5 cm length classes. Trophic niche breadth, food electivity index and Fulton's condition factor of L. laubuca were calculated. Length-weight relationship was determined using the expression, W = aL b. Laubuka laubuca was a euryphagous-planktivorous fish and it showed a size dependent feeding pattern. Young fish had significantly broader (P<0.05) trophic niche breadth than that of adults. According to food electivity indices L. laubuca preferred euglenoids, rotifers, insect larvae, crustacean larvae, arachnid larvae and macrozoobenthos which were highly abundant in stream habitat. Laubuka laubuca showed a positive allometric growth pattern with length-weight relationship of log W =-2.3684 + 3.3528 log TL. Due to high availability of preferred food items in its habitat and positive allometiric growth L. laubuca could be categorised under least concern category in the IUCN Red List.

"1. Human activities affect fish assemblages in a variety of ways. Large-scale and long-term disturbances such as in-stream dredging and mining alter habitat and hydrodynamic characteristics within rivers which can, in turn, alter fish distribution. Habitat heterogeneity is decreased as the natural riffle–pool–run sequences are lost to continuous pools and, as a consequence, lotic species are displaced by lentic species, while generalist and invasive species displace native habitat specialists. Sediment and organic detritus accumulate in deep, dredged reaches and behind dams, disrupting nutrient flow and destroying critical habitat for habitat specialist species.

2. We used standard ecological metrics such as species richness and diversity, as well as stable isotope analysis of δ13C and δ15N, to quantify the differences in fish assemblages sampled by benthic trawls among dredged and undredged sites in the Allegheny River, Pennsylvania, U.S.A.

3. Using mixed-effects models, we found that total catch, species richness and diversity were negatively correlated with depth (P < 0.05), while species richness, diversity and proportion of species in lithophilic (‘rock-loving’) reproductive guilds were lower at dredged than at undredged sites (P < 0.05).

4. Principal components analysis and manova revealed that taxa such as darters in brood hider and substratum chooser reproductive guilds were predominantly associated with undredged sites along principal component axis 1 (PC1 and manovaP < 0.05), while nest spawners such as catfish and open substratum spawners including suckers were more associated with dredged sites along PC2 (P < 0.05).

5. Stable isotope analysis of δ13C and δ15N revealed shifts from reliance on shallow water and benthic-derived nutrients at undredged sites to reliance on phytoplankton and terrestrial detritus at deep-water dredged sites. Relative trophic positions were also lower at dredged sites for many species; loss of benthic nutrient pathways associated with depth and dredging history is hypothesised.

6. The combination of ecological metrics and stable isotope analysis thus shows how anthropogenic habitat loss caused by gravel dredging can decrease benthic fish abundance and diversity, and that species in substratum-specific reproductive guilds are at particular risk. The effects of dredging also manifest by altering resource use and nutrient pathways within food webs. Management and conservation decisions should therefore consider the protection of relatively shallow areas with suitable substratum for spawning for the protection of native fishes."

We report on the incidence of poxvirus-like lesions assessed by photographic identification in two estuarine populations of bottlenose dolphins (Tursiops aduncus) in Australia over a 3-year period. Poxvirus infections of odontocetes are characterized by pinhole or ring-like skin lesions that appear as solitary or coalesced circular gray blemishes. Environmental and physiological stressors are believed to contribute to their manifestation (Van Bressem et al., 2009b). A total of 187 boat-based surveys were completed from October 2003 to September 2006 in the Clarence River (CR) and Richmond River (RR) estuaries, with 720 dolphins sighted. Forty-six individuals, including calves, were identified in the CR and 23 in the RR. We investigated the temporal relationship between four flood events that occurred in the region during the study period and the occurrence of poxvirus-like skin lesions. Dolphin poxvirus-like lesions were not observed in these populations prior to 2004. Following flood events in 2004, 2005 and 2006, a total of 10 new cases were observed, 6 in the CR and 4 in the RR. Our data suggest that the occurrence of dolphin poxvirus-like lesions may be an indicator for climatic events such as flooding. Long-term follow-up of these estuarine populations is required to further clarify the factors leading to ‘outbreaks’ of poxvirus infections.

This paper will determine the limiting nutrient within Elterwater, Esthwaite, 9 Windermere North, and Windermere South Lake Basins. It has been hypothesised 10 that Elterwater and Esthwaite (two Eutrophic basins) should be Nitrogen-limited, whilst 11 Windermere North and Windermere South (two Mesotrophic basins) would be limited 12 by Phosphorous. An algal bioassay was performed on integrated water samples from 13 each of the four basins. The data showed Windermere North and South to be 14 Phosphorous-limited, whilst Elterwater was Nitrogen-limited, however it was unclear 15 whether this was significant. Esthwaite had no obvious trends. A two-tailed T-test was 16 established which showed that the data for Elterwater was significant, and it was 17 limited by Nitrogen. It confirmed the statistical significance of the results for 18 Windermere North and Windermere South, and showed any deviations from the 19 Control in the water taken from the Esthwaite basin in the enriched samples were not 20 statistically significant. All T-tests were done to 95% or 99% confidence limits. It has 21 been concluded that Windermere North and South were Phosphorous-limited, whilst 22 Elterwater was Nitrogen-limited, and these hypotheses were accepted. The 23 hypothesis for Esthwaite was rejected as neither Nitrogen nor Phosphorous were 24 limiting. The chemical composition of a lake is crucial for the survival of the organisms 25 in that water body. It is worthwhile studying why Phosphorous is limiting in 26 Windermere, and why Nitrogen is limiting in Elterwater in order to improve water 27 quality. Further study is needed into the Esthwaite Lake Basin to discover which 28 nutrient is limiting, before the water quality can be improved.

The seacoast of Khar Danda 18.96°N and 72.82°E is to the western edge of Mumbai shore of Bandra Suburb at an altitude of 10m to 15m. It has a tropical climate and temperature varying from min 18°C to max 37°C. The sea line is marked by black Deccan basalt sea rocks. It receives torrential Indian Ocean monsoon rains, between June and September. The Khar-Danda fishing village in the south is the oldest area where Koli community resides to the north is the Carter road Promenade. Human activities like domestic, agricultural or industrial have an impact on water and the ecosystems. Fish farming is the important occupation and several other anthropogenic activities like cremation of dead bodies, domestic sewage, and fecal discharge has tremendously affected the ecosystem of the shore as well as the sea. About 11,494 industries are located in the city and 24,554 industries are located in suburbs, contributing as the major source of industrial pollutants. Nearly half of the Mumbai's populations about 42% of residents are slum dwellers or homeless lacking sewage and sanitation facilities. They use coastal areas as a natural toilet which results in a huge amount of sewage released directly into the sea. A massive amount of these wastes enter the coastal water in and around Khar Danda which is under the grip of pollution. These pollutants carry soil and particles laden with carbon, nitrogen, phosphorus, and minerals. This nutrient-rich water can cause fleshy algae and phytoplankton to thrive in coastal areas; known as algal blooms, which have the potential to create hypoxic conditions by using all available oxygen. Moreover, a drastic depletion in faunal and floral diversity of the area has been observed causing destruction of mangroves as well as a decline in fishery catches. The Pomfret catch has declined from 24,000 tons in 1982 to 3,000 tons in 2006-07. Also, the Bombay duck catch has crashed from 80,000 tons in 1982 to 23,000 in 2006 (Times of India by S.S.Singh.2010). The Physio-chemical parameters like temperature, pH, Hardness, D.O, B.O.D, CO2, Nitrate, Nitrite, Fecal Coliform (FC) and Total Coliform (TC) studied are presented as a minimum, maximum and mean values to assess the extent of water quality variation throughout the year from OCT. 2017 to SEPT. 2018. The result indicated that parameters were found to be greatly affected.

This paper describes a conceptual model created to represent the submerged aquatic vegetation growth and the differential equations that are the product of the first phase of dynamic modeling process. This one is composed of four phases: formulation, verification, calibration and analysis and evaluation.
The problem of excessive macrophytes growth in reservoirs has caused many economic losses, since it is necessary to stop producing eletric energy to remove plants that obstruct turbines. Besides, it reduces the multiple uses of water body. The aim of this work is to present a model that can be used in spatio-temporal simulation to generate a geographic distribution of plants and their development during a period of time. The
state variables were selected based on previous works about modeling and limnology focused on submerged macrophytes, mainly Egeria najas and Egeria densa species. The diagram of conceptual model was designed with the energy language proposed by Odum, which allows to get the mathematical formulation in an easier way than writing it from scratch. The spatial dimension was described adoting the diffusion process and the cellular automata approach. The construction of a diagram to represent an abstraction of problem has the
advantage of facilitating the comprehension of interactions among related variables. Furthermore, it gives us a way of getting the equations that will be used in the next phase of modeling, when formulae will be implemented.

Freshwaters are among the most threatened ecosystems, particularly in North Africa where urbanization and climate change are exerting an important pressure on aquatic fauna. Longterm investigation of macroinvertebrates is one of the best ways of tracking and understanding the influence of environmental and anthropogenic pressures on community dynamics. In this study, we focus on determining the community structure and diversity of benthic macroinvertebrates as well as the state of aquatic physicochemical parameters in the Bouhamdane Stream, near the outlet of
Bouhamdane dam, Seybouse watershed, north-eastern Algeria. We carried out a bi-monthly sampling of macroinvertebrates and nine water physicochemical parameters from September 2017 to July
2018 at three sites. Results show that the collected macroinvertebrates (6756 individuals) belong to 15 families and 12 orders. The abundance of the macrofauna consisted of 88.19% crustaceans,
7.74% insects, 3.7% molluscs and 0.16% annelids. Physicochemical analyzes (depth, turbidity, pH, dissolved O2, temperature, salinity, and conductivity) showed variability among sites. The families
of Gammaridae and Baetidae were the most frequent and the most abundant on all the stations. The results indicate that aquatic macroinvertebrates constitute good indicators of the biological quality of water. This study shows that even with the occurrence of regular dam water discharge, the macroinvertebrate community is still able to persist either through adaptation to high water velocity or high colonization rate.

Original name:
Островский И.С. Оценка параметров уравнений параболического роста и их температурных зависимости у личинок Chironomus plumosus L. // Вид в ареале биология, экология и продуктивность водных беспозвоночных (Гл. ред. Хмелева Н.Н.) - Минск.: Навука i тэхнiка, 1990.- С. 79-84.

The role of women in gleaning fisheries tends to be underestimated and poorly documented although they play an important role in coastal food security and income generation. This article describes two initiatives for co-management of women dominated cockle (Anadara spp.) fisheries implemented in Zanzibar Island of Tanzania and in Nicaragua that were based on a Fiji model. In each case, significant progress was made at the pilot scale but required adaptation to the community and national context. The Nicaragua case resulted in increasing densities of cockles inside and outside small scale no-take zones in a small estuary after a two-year period of implementation. In Zanzibar, out of several no-take sites established on reef flats, only one showed similar results. Other sites’ poor performance is likely due to poor site selection, small size, and non-compliance. Varying degrees of poaching affected both locations and continues to be an issue. In Zanzibar, local and national government played highly supporting roles whereas in Nicaragua, local government was supportive but national government continues to exhibit top-down decision-making, while still evaluating the alternative co-management approach. In both cases, university extension initiatives were influential in building community capacity for management and playing an advocacy role with national government. Both locations are poised for scaling up to more geographic sites as well as fostering policy change that can lead to more integrated and ecosystem-scale approaches to sustainable fisheries management.

A study of macroinvertebrate distribution in relation to different levels of human and animal physical disturbance
of the sediments of the Njoro (highly disturbed) and Ellegirini (less disturbed) rivers was conducted from October 2001 to June 2002, and again in 2012 only in the Njoro River. The rivers have similar climate and land-use characteristics but differ in the frequency and intensity of human and animal disturbance of their sediment surfaces. Benthic macroinvertebrates were sampled during both low discharge, when the disturbances were high, and high discharge, when the disturbances were low. Macroinvertebrate abundance and diversity were higher in the Ellegirini than in the Njoro River. Sites characterised by high disturbance had low macroinvertebrate abundance and diversity, and were dominated by one taxon that tolerated disturbance irrespective of flow regimes. A consistent decline in macroinvertebrate abundance and diversity in the Njoro River as a result of increased disturbance was evident in 2001–2002 and 2012. Macroinvertebrates are most probably redistributed via migration and dispersal, due to these physical disturbances.

"The effects of sample fixation with alcohol and formaldehyde on length (L)-weight (W) relationship of chironomid larvae were quantified. Using the obtained relationships between fresh and preserved weights of larvae, the available data on length-weight relationship of Chironomus plumosus in various populations were converted into the same units relating the fresh weight of larvae with their length (W = aL^b).  The results show that growth allometry of larvae explicitly alters along a latitudinal gradient. The power index (b) of the unified length-weight relationships in different populations decreases from the south to the north in a way that weights for larvae at smaller lengths  are notably higher in more northern areas. 

Original name: Островский, И. С. 1983. Соотношение длины и веса у личинок Chironomus plumosus L. (Chironomidae, Diptera) в разных точках ареала и влияние на него способов фиксации.
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Knowledge about the spatial and temporal scales of both habitat use and the functional significance of different adaptations is essential for an understanding of the population dynamics of invertebrate assemblages. This fundamental knowledge is not only interesting from an academic point of view, but is sorely lacking and needed in the field of restoration ecology. Many species are threatened due to degradation. Knowing what
environmental conditions are needed during the life cycle of these species is important in the design of restoration measures which aim to lift existing bottlenecks for threatened species.

To assess the relative importance of water type and microhabitat in structuring the invertebrate assemblage during different seasons, invertebrates were sampled in three water bodies differing in trophic level and acidity. Different parts within a water body (microhabitats) were sampled separately and each water body was sampled in all four seasons.

Results show that water body is an important factor structuring the invertebrate assemblage early in the season, whereas microhabitat became more important later in the season. Structural complexity of microhabitats was related to the type of locomotion employed by invertebrates. Seasonal differences could be related to population dynamics (reproduction, mortality). Moreover, fluctuations in resource availability were expected to differ between the water bodies, with highest fluctuations in the eutrophic water body and with fluctuations becoming less predictable later in the season. This was confirmed by the data: species synchronization to pulses in food availability was strongest in the eutrophic water body. Moreover, synchronization was strongest in summer, while in autumn waters were invaded by dispersive species.

Based on these results a synthesis is presented on the functioning of the different waters during the different seasons.

There is increasing recognition that not only men, but women and children make significant contributions to the fisheries sector. However, the role of women and children in gleaning fisheries tends to be underestimated and poorly documented although they make significant contributions ...

Morden, A.L., D.B. Conn, A.P. Hendry, and A. Ricciardi. 2015. Interpopulation variation in hypoxia tolerance of the invasive Asian Clam.  New Views – New Tools: Proceedings of the 58th Annual Conference on Great Lakes Research, 25-29 May 2015. International Association of Great Lakes Research, Burlington, Vermont, USA.